Market speculation put forward a possible German bidder or a UK building society, or Invesco, the Anglo/American fund manager, now rebuilding its reputation after its involvement in the Maxwell pensions saga.
The company rejected such speculation. A spokesman said: "We are an independently minded business and always have been. We will stem the client losses, and this will take a great deal of effort and application. It will not be a quick fix."
The pension fund operation has been the problem, while the UK retail and the international businesses have down well, according to the company. Dugald Eadie was brought in from WM Group last year specifically to turn the £5.5bn pension fund business around.
Potential profits in pension fund management are high, but winning and maintaining business depends on consistent good showings in the industry's performance tables.
An observer noted that Henderson's pension fund performance had been "Ok", but this was not good enough in the intensely competitive market.
Henderson has recently lost pension fund business from The Telegraph group and Cumbria County Council.
It also suffered from the defection of Paul Manduca, the Touche Remnant executive who was tipped for the top but who left nine months ago to join Threadneedle Asset Management.
In a trading statement yesterday the company said: "The growth in the retail and international business areas witnessed in the first half has continued and further gains have been achieved.
The management of pension funds remains a key element of our business but significant client losses have continued."
Any takeover would have to be agreed by Henderson family interests that still hold over a quarter of the company, and by the company's broker Cazenove.